The invention is based on a priority application DE 202004009866.0 which is hereby incorporated by reference.
The invention relates to a heat sink arrangement with a heat sink with a circular-cylindrical interior, in particular a casing of an electric motor or casing part for such, with power electronics integrated into the casing or casing part, with at least one electronics component pressed against the heat sink from inside, an electric motor and a casing part.
Using FIG. 2, firstly the electronics part of a commercially available electric motor is described.
The casing of the electric motor is extended beyond the mechanical part of the motor in such a way that it also accommodates the electronics part with integrated power electronics. The casing therefore acts as heat sink 1 and can thus remove the dissipated heat from the power electronics. A slotted cooling ring 2 is clamped in this part of the casing by means of a spring element 3 inserted into the slot and expanding the cooling ring 2. The cooling ring 2 is cylindrical on its outside, in order to lie smoothly against the inside of the casing acting as heat sink. On its inside the cooling ring 2 has flat support faces; it additionally has threads. An electronics component 4 can be pressed on to each of these flat support faces by means of screws and flat springs 5, as part of the integrated power electronics.
In this initial example the entire power electronics is placed on a circular conductor plate and the electronics components to be cooled are mounted perpendicular in a circle. In this way the electronics components are connected, in a thermally excellent manner, to the entire motor casing, which therefore acts as a whole as heat sink.
There are also electric motors available in which the electromechanical and power electronics part are in separate casing parts flanged to one another.
However, this makes assembly of the electronics components on the inside of the cooling ring anything but easy.